α,α′-substituted n-alkyl-3-alkenylbenzoyl-pyrazol-derivatives

ABSTRACT

Pyrazoles of the formula I                    
     where: 
     R 1  is hydrogen, nitro, halogen, cyano, thiocyanato or an aliphatic radical; 
     R 2  is a substituted sulfur, nitrogen or phosphorus atom; 
     R 3  is hydrogen, halogen or an aliphatic radical; 
     R 4 , R 5  are hydrogen, nitro, halogen, cyano, thiocyanato, or an aliphatic radical; 
     R 6  is hydrogen, halogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, C 3 -C 8 -cycloalkyl; 
     R 7 , R 8 , R 9  are hydrogen, C 1 -C 6 -alkyl, but at most one of the radicals R 7 , R 8  and R 9  is hydrogen; 
     and their tautomers and agriculturally useful salts are described. 
     Moreover, the invention relates to processes for preparing compounds of the formula I, to compositions comprising them and to the use of the compounds of the formula I and of the compositions comprising them for controlling harmful plants.

This application is a 371 of PCT/EP00/05857 filed Jun. 23, 2000.

The present invention relates to α,α′-substitutedN-alkyl-3-alkenylbenzoylpyrazole derivatives of the formula I

where:

R¹ is hydrogen, nitro, halogen, cyano, thiocyanato, C₁-C₆-alkyl,C₁-C₆-alkoxy, C₁-C₆-haloalkyl, C₁-C₆-alkylthio, C₂-C₆-alkenyl,C₂-C₆-alkynyl;

R² is —S(O)_(n)R¹⁰, —SO₂OR¹¹, —SO₂NR¹¹R¹², —NR¹²SO₂R¹³, —NR¹²COR¹³,—PO(OR¹⁴)(OR¹⁵);

R³ is hydrogen, halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy,C₂-C₆-alkenyl or C₂-C₆-alkynyl;

R⁴, R⁵ are hydrogen, nitro, halogen, cyano, thiocyanato, C₁-C₆-alkyl,C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, C₂-C₆-alkenyl, C₄-C₆-cycloalkenyl,C₂-C₆-alkynyl, C₁-C₆-alkylthio, C₁-C₆-haloalkoxy, —COR¹⁴, —CO₂R¹⁴,—COSR¹⁴, —CONR¹⁴R¹⁵, —C(R¹⁶)═NR¹⁷, —PO(OR¹⁴)(OR¹⁵), C₁-C₄-alkyl, whichcarries a radical from the following group: —COR¹⁴, —CO₂R¹⁴, —COSR¹⁴,—CONR¹⁴R¹⁵ or —C(R¹⁶)═NR¹⁷; heterocyclyl, heterocyclyl-C₁-C₄-alkyl,phenyl, phenyl-C₁-C₄-alkyl, hetaryl or hetaryl-C₁-C₄-alkyl, where thesix last-mentioned radicals may be substituted;

or

R⁴ and R⁵ together form a C₂-C₆-alkanediyl chain which may be mono- totetrasubstituted by C₁-C₄-alkyl and/or may be interrupted by oxygen orsulfur or an unsubstituted or C₁-C₄-alkyl-substituted nitrogen;

R⁶ is hydrogen, halogen, C₁-C₆-alkyl, C₁-C₆-alkoxy, C₃-C₈-cycloalkyl;

R⁷, R⁸, R⁹ are hydrogen, C₁-C₆-alkyl, where the alkyl group may beunsubstituted or mono- or polysubstituted by halogen or cyano and theradicals R⁷, R⁸ and R⁹ are in each case identical or different, but atmost one of the radicals from the group R⁷, R⁸ and R⁹ is hydrogen;

n is 0, 1 or 2;

R¹⁰ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy-C₂-C₆-alkyl,C₃-C₆-alkenyl or C₃-C₆-alkynyl;

R¹¹ is hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy-C₂-C₆-alkyl,C₃-C₆-alkenyl or C₃-C₆-alkynyl;

R¹² is hydrogen or C₁-C₆-alkyl;

R¹³ is C₁-C₆-alkyl or C₁-C₆-haloalkyl;

R¹⁴ is hydrogen, C₁-C₆-alkyl, C₃-C₆-cycloalkyl, C₁-C₆-haloalkyl,C₃-C₆-alkenyl, C₃-C₆-alkynyl, phenyl or benzyl, where the twolast-mentioned radicals may be partially or fully halogenated and/or maycarry one to three radicals from the following group: nitro, cyano,C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy,C₁-C₄-alkylcarbonyl or C₁-C₄-alkoxycarbonyl;

R¹⁵ is hydrogen, C₁-C₆-alkyl, C₃-C₆-alkenyl or C₃-C₆-alkynyl;

or

R¹⁴ and R¹⁵ together form a C₂-C₆-alkanediyl chain which may be mono- totetrasubstituted by C₁-C₄-alkyl and/or may be interrupted by oxygen orsulfur or an unsubstituted or C₁-C₄-alkyl-substituted nitrogen;

R¹⁶ is hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy,C₁-C₆-alkoxycarbonyl, C₃-C₆-cycloalkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl,phenyl or benzyl, where the two last-mentioned radicals may be partiallyor fully halogenated and/or may carry one to three radicals from thefollowing group: nitro, cyano, C₁-C₄-alkyl, C₁-C₄-haloalkyl,C₁-C₄-alkoxy, C₁-C₄-haloalkoxy, C₁-C₄-alkylcarbonyl orC₁-C₄-alkoxycarbonyl;

R¹⁷ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, C₃-C₆-alkenyl,C₃-C₆-alkynyl, C₁-C₆-alkoxy, C₁-C₆-haloalkoxy, C₃-C₆-cycloalkoxy,C₃-C₆-alkenyloxy, C₃-C₆-alkynyloxy, phenyl, benzyl or benzyloxy, wherethe three last-mentioned radicals may be partially or fully halogenatedand/or may carry one to three radicals from the following group: nitro,cyano, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy,C₁-C₄-alkylcarbonyl or C₁-C₄-alkoxycarbonyl;

and their tautomers and agriculturally useful salts.

Moreover, the invention relates to processes for preparing compounds ofthe formula I, to compositions comprising them and to the use of thecompounds of the formula I and of the compositions comprising them inthe agronomic field, in particular for controlling undesirablevegetation.

Herbicidally active compounds of the class of the benzoylpyrazoles aredisclosed, for example, in EP-A 282 944; WO 98/42677; WO 98/45273;WO98/50366; WO 98/52926; WO 98/56766; U.S. Pat. No. 5,807,806.

However, the herbicidal properties of these compounds and theircompatibility with crop plants are not entirely satisfactory.

It is an object of the present invention to provide novel compoundshaving improved properties which can be used as active compounds in cropprotection, in particular as herbicides.

We have found that this object is achieved by the benzoylpyrazolesdefined above, which are substituted in the 1-position of the pyrazolederivative by a branched alkyl group. This branched alkyl group ischaracterized by the substitutent —CR⁷R⁸R⁹ on the pyrazole ring.

Furthermore, we have found highly effective compositions comprising thecompounds I. Moreover, we have found processes for preparing thesecompositions and methods for controlling undesirable vegetation usingthe compounds I.

The present invention also provides stereoisomers of the compounds ofthe formula I. This includes both pure stereoisomers and mixturesthereof.

The compounds of the formula I contain a carbon-carbon double bond andare therefore present as E isomers or as z isomers or as E/Z isomermixtures. Furthermore, the compounds of the formula I can containfurther carbon or carbon-nitrogen double bonds. The invention providesboth the pure geometric isomers and mixtures thereof.

Likewise, depending on the substitution pattern, the compounds of theformula I can contain one or more chiral centers, in which case they arepresent as enantiomers or diastereomer mixtures. The invention providesboth the pure enantiomers or diastereomers and mixtures thereof.

The compounds of the formula I can also be present in the form of theirtautomers or as tautomer mixtures. The tautomeric forms result inparticular owing to the hydroxyl substituent at the pyrazole ring. Thus,the compounds can be referred to both as 5-hydroxypyrazoles and as5-oxo-pyrazolinones.

The present invention also provides precursors which afford compounds Iby chemical conversion or biological degradation. Such precursors ofcompounds I are, for example, esters or ether derivatives of functionalhydroxyl groups.

The compounds of the formula I can also be present in the form of theiragriculturally useful salts, the type of salt generally beingimmaterial. In general, the salts of those cations or the acid additionsalts of those acids are suitable whose cations and anions,respectively, do not adversely affect the herbicidal action of thecompounds I.

Suitable cations are, in particular, ions of the alkali metals,preferably lithium, sodium and potassium, of the alkaline earth metals,preferably calcium and magnesium, and of the transition metals,preferably manganese, copper, zinc and iron, and also ammonium, where,if desired, one to four hydrogen atoms may be replaced by C₁-C₄-alkyl orhydroxy-C₁-C₄-alkyl and/or one phenyl or benzyl, preferablydiisopropylammonium, tetramethylammonium, tetrabutylammonium,trimethylbenzylammonium, furthermore phosphonium ions, sulfonium ions,preferably tri(C₁-C₄-alkyl)-sulfonium and sulfoxonium ions, preferablytri(C₁-C₄-alkyl)-sulfoxonium.

Anions of suitable acid addition salts are primarily chloride, bromide,fluoride, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogenphosphate, nitrate, bicarbonate, carbonate, hexafluorosilicate,hexafluorophosphate, benzoate and the anions of C₁-C₄-alkanoic acids,preferably formate, acetate, propionate and butyrate.

Essential for the invention for the purpose of the present invention arecompounds of the formula I which are substituted by a branched alkylgroup —CR⁷R⁸R⁹ in the 1-position of the pyrazole ring. These are inparticular those compounds I in which at most one of the radicals fromthe group consisting of R⁷, R⁸ and R⁹ is hydrogen and the other tworadicals are different from hydrogen (for example R⁷=H and R⁸≠H, R⁹≠H).

The organic molecular moieties mentioned for the substituents R¹-R¹⁷ arecollective terms for individual enumerations of the individual groupmembers. All hydrocarbon chains, i.e. all alkyl, haloalkyl, cycloalkyl,alkoxyalkyl, alkoxy, haloalkoxy, cycloalkoxy, alkylthio, alkylsulfonyl,haloalkylsulfonyl, alkylcarbonyl, haloalkylcarbonyl, alkoxycarbonyl,alkenyl, cycloalkenyl, alkynyl, alkenyloxy and alkynyloxy moieties canbe straight-chain or branched. Unless indicated otherwise, halogenatedsubstituents preferably carry one to five identical or different halogenatoms. The term halogen in each case denotes fluorine, chlorine, bromineor iodine.

Examples of other meanings are:

C₂-C₄-alkyl: ethyl, n-propyl, 1-methylethyl, butyl, 1-methylpropyl,2-methylpropyl or 1,1-dimethylethyl;

C₁-C₄-alkyl, and the alkyl moieties of, for example,C₁-C₄-alkylcarbonyl, heterocyclyl-C₁-C₄-alkyl, phenyl-C₁-C₄-alkyl andhetaryl-C₁-C₄-alkyl: C₂-C₄-alkyl as mentioned above, and also methyl;

C₂-C₆-alkyl, and the alkyl moieties of, for example,C₁-C₆-alkoxy-C₂-C₆-alkyl: C₂-C₄-alkyl as mentioned above, and alsopentyl 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl,1-ethylpropyl, hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl,1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl,1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl,2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl,2-ethylbutyl, 1,1,2-trimethylpropyl, 1-ethyl-1-methylpropyl or1-ethyl-3-methylpropyl;

C₁-C₆-alkyl, and the alkyl moieties of, for example,C₁-C₆-alkoxy-C₁-C₆-alkyl and C₁-C₆-alkylcarbonyl: C₂-C₆-alkyl asmentioned above, and also methyl;

C₁-C₄-haloalkyl: a C₁-C₄-alkyl radical as mentioned above which ispartially or fully substituted by fluorine, chlorine, bromine and/oriodine, i.e., for example, chloromethyl, dichloromethyl,trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl,chlorofluoromethyl, dichlorofluoromethyl, chlorodifluoromethyl,2-fluoroethyl, 2-chloroethyl, 2-bromoethyl, 2-iodoethyl,2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2-fluoroethyl,2-chloro-2,2-difluoroethyl, 2,2-dichloro-2-fluoroethyl,2,2,2-trichloroethyl, pentafluoroethyl, 2-fluoropropyl, 3-fluoropropyl,2,2-difluoropropyl, 2,3-difluoropropyl, 2-chloropropyl, 3-chloropropyl,2,3-dichloropropyl, 2-bromopropyl, 3-bromopropyl, 3,3,3-trifluoropropyl,3,3,3-trichloropropyl, 2,2,3,3,3-pentafluoropropyl, heptafluoropropyl,1-(fluoromethyl)-2-fluoroethyl, 1-(chloromethyl)-2-chloroethyl,1-(bromomethyl)-2-bromoethyl, 4-fluorobutyl, 4-chlorobutyl, 4-bromobutylor nonafluorobutyl;

C₁-C₆-haloalkyl, and the haloalkyl moieties of C₁-C₆-haloalkylcarbonyl:C₁-C₄-haloalkyl as mentioned above, and also 5-fluoropentyl,5-chloropentyl, 5-bromopentyl, 5-iodopentyl, undecafluoropentyl,6-fluorohexyl, 6-chlorohexyl, 6-bromohexyl, 6-iodohexyl ordodecafluorohexyl;

C₁-C₄-alkoxy, and the alkoxy moieties of C₁-C₄-alkoxycarbonyl: methoxy,ethoxy, propoxy, 1-methylethoxy, butoxy, 1-methylpropoxy,2-methylpropoxy or 1,1-dimethylethoxy;

C₁-C₆-alkoxy, and the alkoxy moieties of C₁-C₆-alkoxy-C₁-C₆-alkyl,C₁-C₆-alkoxy-C₂-C₆-alkyl and C₁-C₆-alkoxycarbonyl: C₁-C₄-alkoxy asmentioned above, and also pentoxy, 1-methylbutoxy, 2-methylbutoxy,3-methylbutoxy, 1,1-dimethylpropoxy, 1,2-dimethylpropoxy,2,2-dimethylpropoxy, 1-ethylpropoxy, hexoxy, 1-methylpentoxy,2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy,1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,2-dimethylbutoxy,2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbutoxy, 2-ethylbutoxy,1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1-ethyl-1-methylpropoxyor 1-ethyl-2-methylpropoxy;

C₁-C₄-haloalkoxy: a C₁-C₄-alkoxy radical as mentioned above which ispartially or fully substituted by fluorine, chlorine, bromine and/oriodine, i.e., for example, fluoromethoxy, difluoromethoxy,trifluoromethoxy, chlorodifluoromethoxy, bromodifluoromethoxy,2-fluoroethoxy, 2-chloroethoxy, 2-bromoethoxy, 2-iodoethoxy,2,2-difluoroethoxy, 2,2,2-trifluoroethoxy, 2-chloro-2-fluoroethoxy,2-chloro-2,2-difluoroethoxy, 2,2-dichloro-2-fluoroethoxy,2,2,2-trichloroethoxy, pentafluoroethoxy, 2-fluoropropoxy,3-fluoropropoxy, 2-chloropropoxy, 3-chloropropoxy, 2-bromopropoxy,3-bromopropoxy, 2,2-difluoropropoxy, 2,3-difluoropropoxy,2,3-dichloropropoxy, 3,3,3-trifluoropropoxy, 3,3,3-trichloropropoxy,2,2,3,3,3-pentafluoropropoxy, heptafluoropropoxy,1-(fluoromethyl)-2-fluoroethoxy, 1-(chloromethyl)-2-chloroethoxy,1-(bromomethyl)-2-bromoethoxy, 4-fluorobutoxy, 4-chlorobutoxy,4-bromobutoxy or nonafluorobutoxy;

C₁-C₆-haloalkoxy: C₁-C₄-haloalkoxy as mentioned above, and also, forexample, 5-fluoropentoxy, 5-chloropentoxy, 5-bromopentoxy,5-iodopentoxy, undecafluoropentoxy, 6-fluorohexoxy, 6-chlorohexoxy,6-bromohexoxy, 6-iodohexoxy or dodecafluorohexoxy;

C₁-C₆-alkylthio: for example, methylthio, ethylthio, propylthio,1-methylethylthio, butylthio, 1-methylpropylthio, 2-methylpropylthio,1,1-dimethylethylthio, pentylthio, 1-methylbutylthio, 2-methylbutylthio,3-methylbutylthio, 2,2-dimethylpropylthio, 1-ethylpropylthio, hexylthio,1,1-dimethylpropylthio, 1,2-dimethylpropylthio, 1-methylpentylthio,2-methylpentylthio, 3-methylpentylthio, 4-methylpentylthio,1,1-dimethylbutylthio, 1,2-dimethylbutylthio, 1,3-dimethylbutylthio,2,2-dimethylbutylthio, 2,3-dimethylbutylthio, 3,3-dimethylbutylthio,1-ethylbutylthio, 2-ethylbutylthio, 1,1,2-trimethylpropylthio,1,2,2-trimethylpropylthio, 1-ethyl-1-methylpropylthio or1-ethyl-2-methylpropylthio;

C₁-C₆-alkylsulfonyl (C₁-C₆-alkyl-S(═O)₂—): for example methylsulfonyl,ethylsulfonyl, propylsulfonyl, 1-methylethylsulfonyl, butylsulfonyl,1-methylpropylsulfonyl, 2-methylpropylsulfonyl or1,1-dimethylethylsulfonyl, pentylsulfonyl, 1-methylbutylsulfonyl,2-methylbutylsulfonyl, 3-methylbutylsulfonyl,2,2-dimethylpropylsulfonyl, 1-ethylpropylsulfonyl,1,1-dimethylpropylsulfonyl, 1,2-dimethylpropylsulfonyl, hexylsulfonyl,1-methylpentylsulfonyl, 2-methylpentylsulfonyl, 3-methylpentylsulfonyl,4-methylpentylsulfonyl, 1,1-dimethylbutylsulfonyl,1,2-dimethylbutylsulfonyl, 1,3-dimethylbutylsulfonyl,2,2-dimethylbutylsulfonyl, 2,3-dimethylbutylsulfonyl,3,3-dimethylbutylsulfonyl, 1-ethylbutylsulfonyl, 2-ethylbutylsulfonyl,1,1,2-trimethylpropylsulfonyl, 1,2,2-trimethylpropylsulfonyl1-ethyl-1-methylpropylsulfonyl or 1-ethyl-2-methylpropylsulfonyl;

C₁-C₆-haloalkylsulfonyl: a C₁-C₆-alkylsulfonyl radical as mentionedabove which is partially or fully substituted by fluorine, chlorine,bromine and/or iodine, i.e. fluoromethylsulfonyl,difluoromethylsulfonyl, trifcluoromethylsulfonyl,chlorodifluoromethylsulfonyl, bromodifluoromethylsulfonyl,2-fluoroethylsulfonyl, 2-chloroethylsulfonyl, 2-bromoethylsulfonyl,2-iodoethylsulfonyl, 2,2-difluoroethylsulfonyl,2,2,2-trifluoroethylsulfonyl, 2,2,2-trichloroethylsulfonyl,2-chloro-2-fluoroethylsulfonyl, 2-chloro-2,2-difluoroethylsulfonyl,2,2-dichloro-2-fluoroethylsulfonyl, pentafluoroethylsulfonyl,2-fluoropropylsulfonyl, 3-fluoropropylsulfonyl, 2-chloropropylsulfonyl,3-chloro propylsulfonyl, 2-bromopropylsulfonyl, 3-bromo propylsulfonyl,2,2-difluoropropylsulfonyl, 2,3-difluoropropylsulfonyl,2,3-dichloropropylsulfonyl, 3,3,3-trifluoropropylsulfonyl,3,3,3-trichloropropylsulfonyl, 2,2,3,3,3-pentafluoropropylsulfonyl,heptafluoropropylsulfonyl, 1-(fluoromethyl)-2-fluoroethylsulfonyl,1-(chloromethyl)-2-chloroethylsulfonyl,1-(bromomethyl)-2-bromoethylsulfonyl, 4-fluorobutylsulfonyl,4-chlorobutylsulfonyl, 4-bromobutylsulfonyl, Nonafluorobutylsulfonyl,5-fluoropentylsulfonyl, 5-chloropentylsulfonyl, 5-bromopentylsulfonyl,5-iodopentylsulfonyl, 6-fluorohexylsulfonyl, 6-bromohexylsulfonyl,6-iodohexylsulfonyl or dodecafluorohexylsulfonyl;

C₃-C₆-alkenyl: prop-1-en-1-yl, prop-2-en-1-yl, 1-methylethenyl,buten-1-yl, buten-2-yl, buten-3-yl, 1-methylprop-3-en-1-yl,2-methylprop-3-en-1-yl, 1-methylprop-2-en-1-yl, 2-methylprop-2-en-1-yl,penten-1-yl, penten-2-yl, penten-3-yl, penten-4-yl,1-methylbut-1-en-1-yl, 2-methylbut-1-en-1-yl, 3-methylbut-1-en-1-yl,1-methylbut-2-en-1-yl, 2-methylbut-2-en-1-yl, 3-methylbut-2-en-1-yl,1-methylbut-3-en-1-yl, 2-methylbut-3-en-1-yl, 3-methylbut-3-en-1-yl,1,1-dimethylprop-2-en-1-yl, 1,2-dimethylprop-1-en-1-yl,1,2-dimethylprop-2-en-1-yl, 1-ethylprop-1-en-2-yl,1-ethylprop-2-en-1-yl, hex-1-en-1-yl, hex-2-en-1-yl, hex-3-en-1-yl,hex-4-en-1-yl, hex-5-en-1-yl, 1-methylpent-1-en-1-yl,2-methylpent-1-en-1-yl, 3-methylpent-1-en-1-yl, 4-methylpent-1-en-1-yl,1-methylpent-2-en-1-yl, 2-methylpent-2-en-1-yl, 3-methylpent-2-en-1-yl,4-methylpent-2-en-1-yl, 1-methylpent-3-en-1-yl, 2-methylpent-3-en-1-yl,3-methylpent-3-en-1-yl, 4-methylpent-3-en-1-yl, 1-methylpent-4-en-1-yl,2-methylpent-4-en-1-yl, 3-methylpent-4-en-1-yl, 4-methylpent-4-en-1-yl,1,1-dimethylbut-2-en-1-yl, 1,1-dimethylbut-3-en-1-yl,1,2-dimethylbut-1-en-1-yl, 1,2-dimethylbut-2-en-1-yl,1,2-dimethylbut-3-en-1-yl, 1,3-dimethylbut-1-en-1-yl,1,3-dimethylbut-2-en-1-yl, 1,3-dimethylbut-3-en-1-yl,2,2-dimethylbut-3-en-1-yl, 2,3-dimethylbut-1-en-1-yl,2,3-dimethylbut-2-en-1-yl, 2,3-dimethylbut-3-en-1-yl,3,3-dimethylbut-1-en-1-yl, 3,3-dimethylbut-2-en-1-yl,1-ethylbut-1-en-1-yl, 1-ethylbut-2-en-1-yl, 1-ethylbut-3-en-1-yl,2-ethylbut-1-en-1-yl, 2-ethylbut-2-en-1-yl, 2-ethylbut-3-en-1-yl,1,1,2-trimethylprop-2-en-1-yl, 1-ethyl-1-methylprop-2-en-1-yl,1-ethyl-2-methylprop-1-en-1-yl or 1-ethyl-2-methylprop-2-en-1-yl;

C₂-C₆-alkenyl: C₃-C₆-alkenyl as mentioned above, and also ethenyl;

C₃-C₆-alkenyloxy: for example prop-1-en-1-yloxy, prop-2-en-1-yloxy,1-methylethenyloxy, buten-1-yloxy, buten-2-yloxy, buten-3-yloxy,1-methylprop-1-en-1-yloxy, 2-methylprop-1-en-1-yloxy,1-methylprop-2-en-1-yloxy, 2-methylprop-2-en-1-yloxy, penten-1-yloxy,penten-2-yloxy, penten-3-yloxy, penten-4-yloxy,1-methylbut-1-en-1-yloxy, 2-methylbut-1-en-1-yloxy,3-methylbut-1-en-1-yloxy, 1-methylbut-2-en-1-yloxy,2-methylbut-2-en-1-yloxy, 3-methylbut-2-en-1-yloxy,1-methylbut-3-en-1-yloxy, 2-methylbut-3-en-1-yloxy,3-methylbut-3-en-1-yloxy, 1,1-dimethylprop-2-en-1-yloxy,1,2-dimethylprop-1-en-1-yloxy, 1,2-dimethylprop-2-en-1-yloxy,1-ethylprop-1en-2-yloxy, 1-ethylprop-2-en-1-yloxy, hex-1-en-1-yloxy,hex-2-en-1-yloxy, hex-3-en-1-yloxy, hex-4-en-1-yloxy, hex-5-en-1-yloxy,1-methylpent-1-en-1-yloxy, 2-methylpent-1-en-1-yloxy,3-methylpent-1-en-1-yloxy, 4-methylpent-1-en-1-yloxy,1-methylpent-2-en-1-yloxy, 2-methylpent-2-en-1-yloxy,3-methylpent-2-en-1-yloxy, 4-methylpent-2-en-1-yloxy,1-methylpent-3-en-1-yloxy, 2-methylpent-3-en-1-yloxy,3-methylpent-3-en-1-yloxy, 4-methylpent-3-en-1-yloxy,1-methylpent-4-en-1-yloxy, 2-methylpent-4-en-1-yloxy,3-methylpent-4-en-1-yloxy, 4-methylpent-4-en-1-yloxy,1,1-dimethylbut-2-en-1-yloxy, 1,1-dimethylbut-3-en-1-yloxy,1,2-dimethylbut-1-en-1-yloxy, 1,2-dimethylbut-2-en-1-yloxy,1,2-dimethylbut-3-en-1-yloxy, 1,3-dimethylbut-1-en-1-yloxy,1,3-dimethylbut-2-en-1-yloxy, 1,3-dimethylbut-3-en-1-yloxy,2,2-dimethylbut-3-en-1-yloxy, 2,3-dimethylbut-1-en-1-yloxy,2,3-dimethylbut-2-en-1-yloxy, 2,3-dimethylbut-3-en-1-yloxy,3,3-dimethylbut-1-en-1-yloxy, 3,3-dimethylbut-2-en-1-yloxy,1-ethylbut-1-en-1-yloxy, 1-ethylbut-2-en-1-yloxy,1-ethylbut-3-en-1-yloxy, 2-ethylbut-1-en-1-yloxy,2-ethylbut-2-en-1-yloxy, 2-ethylbut-3-en-1-yloxy,1,1,2-trimethylprop-2-en-1-yloxy, 1-ethyl-1-methylprop-2-en-1-yloxy,1-ethyl-2-methylprop-1-en-1-yloxy or 1-ethyl-2-methylprop-2-en-1-yloxy;

C₃-C₆-alkynyl: prop-1-yn-1-yl, prop-2-yn-1-yl, but-1-yn-1-yl,but-1-yn-3-yl, but-1-yn-4-yl, but-2-yn-1-yl, pent-1-yn-1-yl,pent-1-yn-3-yl, pent-1-yn-4-yl, pent-1-yn-5-yl, pent-2-yn-1-yl,pent-2-yn-4-yl, pent-2-yn-5-yl; 3-methylbut-1-yn-3-yl,3-methylbut-1-yn-4-yl, hex-1-yn-1-yl, hex-1-yn-3-yl, hex-1-yn-4-yl,hex-1-yn-5-yl, hex-1-yn-6-yl, hex-2-yn-1-yl, hex-2-yn-4-yl,hex-2-yn-5-yl, hex-2-yn-6-yl, hex-3-yn-1-yl, hex-3-yn-2-yl,3-methylpent-1-yn-1-yl, 3-methylpent-1-yn-3-yl, 3-methylpent-1-yn-4-yl,3-methylpent-1-yn-5-yl, 4-methylpent-1-yn-1-yl, 4-methylpent-2-yn-4-ylor 4-methylpent-2-yn-5-yl;

C₂-C₆-alkynyl: C₃-C₆-alkynyl as mentioned above, and also ethynyl:

C₃-C₆-alkynyloxy: for example prop-1-yn-1-yloxy, prop-2-yn-1-yloxy,but-1-yn-1-yloxy, but-1-yn-3-yloxy, but-1-yn-4-yloxy, but-2-yn-1-yloxy,pent-1-yn-1-yloxy, pent-1-yn-3-yloxy, pent-1-yn-4-yloxy,pent-1-yn-5-yloxy, pent-2-yn-1-yloxy, pent-2-yn-4-yloxy,pent-2-yn-5-yloxy, 3-methylbut-1-yn-3-yloxy, 3-methylbut-1-yn-4-yloxy,hex-1-yn-1-yloxy, hex-1-yn-3-yloxy, hex-1-yn-4-yloxy, hex-1-yn-5-yloxy,hex-1-yn-6-yloxy, hex-2-yn-1-yloxy, hex-2-yn-4-yloxy, hex-2-yn-5-yloxy,hex-2-yn-6-yloxy, hex-3-yn-1-yloxy, hex-3-yn-2-yloxy,3-methylpent-1-yn-1-yloxy, 3-methylpent-1-yn-3-yloxy,3-methylpent-1-yn-4-yloxy, 3-methylpent-1-yn-5-yloxy,4-methylpent-1-yn-1-yloxy, 4-methylpent-2-yn-4-yloxy or4-methylpent-2-yn-5-yloxy;

C₃-C₆-cycloalkyl: cyclopropyl, cyclobutyl, cycl or cyclohexyl;

C₃-C₆-cycloalkoxy: cyclopropoxy, cyclobutoxy, cyclopentoxy orcyclohexoxy;

C₃-C₆-cycloalkenyl: cyclopropen-1-yl, cyclobuten-3-yl, cyclopenten-1-yl,cyclopenten-3-yl, cyclohexen-1-yl, cyclohexen-3-yl or cyclohexen-4-yl;

heterocyclyl, and the heterocyclyl radicals in heterocyclyloxy andheterocyclyl-C₁-C₄-alkyl: three- to seven-membered saturated orpartially unsaturated mono- or polycyclic heterocycles containing one tothree hetero atoms selected from a group consisting of oxygen, nitrogenand sulfur, such as oxiranyl, 2-tetrahydrofuranyl, 3-tetrahydrofuranyl,2-tetrahydrothienyl, 3-tetrahydrothienyl, 2-pyrrolidinyl,3-pyrrolidinyl, 3-isoxazolidinyl, 4-isoxazolidinyl, 5-isoxazolidinyl,3-isothiazolidinyl, 4-isothiazolidinyl, 5-isothiazolidinyl,3-pyrazolidinyl, 4-pyrazolidinyl, 5-pyrazolidinyl, 2-oxazolidinyl,4-oxazolidinyl, 5-oxazolidinyl, 2-thiazolidinyl, 4-thiazolidinyl,5-thiazolidinyl, 2-imidazolidinyl, 4-imidazolidinyl,1,2,4-oxadiazolidin-3-yl, 1,2,4-oxadiazolidin-5-yl,1,2,4-thiadiazolidin-3-yl, 1,2,4-thiadiazolidin-5-yl,1,2,4-triazolidin-3-yl, 1,3,4-oxadiazolidin-2-yl,1,3,4-thiadiazolidin-2-yl, 1,3,4-triazolidin-2-yl,2,3-dihydrofuran-2-yl, 2,3-dihydrofuran-3-yl, 2,3-dihydrofuran-4-yl,2,3-dihydrofuran-5-yl, 2,5-dihydrofuran-2-yl, 2,5-dihydrofuran-3-yl,2,3-dihydrothien-2-yl, 2,3-dihydrothien-3-yl, 2,3-dihydrothien-4-yl,2,3-dihydrothien-5-yl, 2,5-dihydrothien-2-yl, 2,5-dihydrothien-3-yl,2,3-dihydropyrrol-2-yl, 2,3-dihydropyrrol-3-yl, 2,3-dihydropyrrol-4-yl,2,3-dihydropyrrol-5-yl, 2,5-dihydropyrrol-2-yl, 2,5-dihydropyrrol-3-yl,2,3-dihydroisoxazol-3-yl, 2,3-dihydroisoxazol-4-yl,2,3-dihydroisoxazol-5-yl, 4,5-dihydroisoxazol-3-yl,4,5-dihydroisoxazol-4-yl, 4,5-dihydroisoxazol-5-yl,2,5-dihydroisoxazol-3-yl, 2,5-dihydroisoxazol-4-yl,2,5-dihydroisoxazol-5-yl, 2,3-dihydroisothiazol-3-yl,2,3-dihydroisothiazol-4-yl, 2,3-dihydroisothiazol-5-yl,4,5-dihydroisothiazol-3-yl, 4,5-dihydroisothiazol-4-yl,4,5-dihydroisothiazol-5-yl, 2,5-dihydroisothiazol-3-yl,2,5-dihydroisothiazol-4-yl, 2,5-dihydroisothiazol-5-yl,2,3-dihydropyrazol-3-yl, 2,3-dihydropyrazol-4-yl,2,3-dihydropyrazol-5-yl, 4,5-dihydropyrazol-3-yl,4,5-dihydropyrazol-4-yl, 4,5-dihydropyrazol-5-yl,2,5-dihydropyrazol-3-yl, 2,5-dihydropyrazol-4-yl,2,5-dihydropyrazol-5-yl, 2,3-dihydroxazol-2-yl, 2,3-dihydroxazol-4-yl,2,3-dihydroxazol-5-yl, 4,5-dihydroxazol-2-yl, 4,5-dihydroxazol-4-yl,4,5-dihydroxazol-5-yl, 2,5-dihydroxazol-2-yl, 2,5-dihydroxazol-4-yl,2,5-dihydroxazol-5-yl, 2,3-dihydrothiazol-2-yl, 2,3-dihydrothiazol-4-yl,2,3-dihydrothiazol-5-yl, 4,5-dihydrothiazol-2-yl,4,5-dihydrothiazol-4-yl, 4,5-dihydrothiazol-5-yl,2,5-dihydrothiazol-2-yl, 2,5-dihydrothiazol-4-yl,2,5-dihydrothiazol-5-yl, 2,3-dihydroimidazol-2-yl,2,3-dihydroimidazol-4-yl, 2,3-dihydroimidazol-5-yl,4,5-dihydroimidazol-2-yl, 4,5-dihydroimidazol-4-yl,4,5-dihydroimidazol-5-yl, 2,5-dihydroimidazol-2-yl,2,5-dihydroimidazol-4-yl, 2,5-dihydroimidazol-5-yl, 2-morpholinyl,3-morpholinyl, 2-piperidinyl, 3-piperidinyl, 4-piperidinyl,3-tetrahydropyridazinyl, 4-tetrahydropyridazinyl,2-tetrahydropyrimidinyl, 4-tetrahydropyrimidinyl,5-tetrahydropyrimidinyl, 2-tetrahydropyrazinyl,1,3,5-tetrahydrotriazin-2-yl, 1,2,4-tetrahydrotriazin-3-yl,1,3-dihydroxazin-2-yl, 2-tetrahydropyranyl, 3-tetrahydropyranyl,4-tetrahydropyranyl, 2-tetrahydrothiopyranyl, 3-tetrahydrothiopyranyl,4-tetrahydrothiopyranyl, 1,3-dioxolan-2-yl, 1,3-dioxolan-4-yl,1,3-dithiolan-2-yl, 1,3-dithiolan-4-yl, 1,3-dioxan-2-yl,1,3-dioxan-4-yl, 1,3-dioxan-5-yl, 1,3-dithian-2-yl, 1,3-dithian-4-yl,1,3-dithian-5-yl, 3,4,5,6-tetrahydropyridin-2-yl, 4H-1,3-thiazin-2-yl,4H-3,1-benzothiazin-2-yl, 1,1-dioxo-2,3,4,5-tetrahydrothien-2-yl,2H-1,4-benzothiazin-3-yl, 2H-1,4-benzoxazin-3-yl or1,3-dihydroxazin-2-yl;

hetaryl, and the heteraryl radicals in hetaryloxy andhetaryl-C₁-C₄-alkyl: aromatic mono- or polycylclic radicals which, inaddition to carbon ring members, may additionally contain one to fournitrogen atoms or one to three nitrogen atoms and one oxygen or onesulfur atom or one oxygen or one sulfur atom, for example, 2-furyl,3-furyl, 2-thienyl, 3-thienyl, 2-pyrrolyl, 3-pyrrolyl, 3-isoxazolyl,4-isoxazolyl, 5-isoxazolyl, 3-isothiazolyl, 4-isothiazolyl,5-isothiazolyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, 2-oxazolyl,4-oxazolyl, 5-oxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl,2-imidazolyl, 4-imidazolyl, 1,2,4-oxadiazol-3-yl, 1,2,4-oxadiazol-5-yl,1,2,4-thiadiazol-3-yl, 1,2,4-thiadiazol-5-yl, 1,2,4-triazol-3-yl,1,3,4-oxadiazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,3,4-triazol-2-yl,2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 3-pyridazinyl, 4-pyridazinyl,2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 2pyrazinyl,1,3,5-triazin-2-yl, 1,2,4-triazin-3-yl, 1,2,4,5-tetrazin-3-yl, and thecorresponding benzo-fused derivatives;

C₂-C₆-alkanediyl: for example ethane-1,2-diyl, propane-1,3-diyl,butane-1,4-diyl, pentane-1,5-diyl or hexane-1,6-diyl;

All of the abovementioned phenyl, hetaryl and heterocyclyl rings can besubstituted or unsubstituted. They are preferably unsubstituted.Substituted rings carry one to three halogen atoms and/or one or tworadicals from the following group: nitro, cyano, C₁-C₆-alkyl,halo-C₁-C₆-alkyl, C₁-C₆-alkoxy, halo-C₁-C₆-alkoxy orC₁-C₆-alkoxycarbonyl, such as, for example, methyl, trifluoromethyl,methoxy, trifluoromethoxy or methoxycarbonyl.

Precursors of compounds I are, for example, ester or ether derivativesof functional hydroxyl groups. In this context, they are to beunderstood as meaning, in particular, those compounds of the formula Iin which the hydroxyl group on the pyrazole ring is replaced by thefollowing radicals: C₁-C₆-alkoxy, C₃-C₆-alkenyloxy,C₁-C₆-alkylsulfonyloxy, C₁-C₆-alkylcarbonyloxy, phenoxy-,phenyl-C₁-C₄-alkoxy, phenylcarbonyl-C₁-C₄-alkoxy, phenylsulfonyloxy,where the phenyl radical of the four lastmentioned substitutents may bepartially or fully halogenated and/or may carry one to three of thefollowing groups: nitro, cyano, C₁-C₄-alkyl, C₁-C₄-haloalkyl,C₁-C₄-alkoxy or C₁-C₄-haloalkoxy.

With respect to the use of the compounds of the formula I according tothe invention as herbicides, the variables preferably have the followingmeanings, in each case on their own or in combination with one another,and some substituents, which fall under the general terms mentionedunder a) are listed by way of example below, under b):

1. R¹:

a) C₁-C₆-alkyl, C₁-C₆-alkoxy, halogen

b) methyl, methoxy, chlorine

2. R² is preferably in the para position to the pyrazolyl carbonyl groupand is, in particular:

a) C₁-C₆-alkylsulfonyl

b) methylsulfonyl, ethylsulfonyl

3. R³

a) hydrogen, C₁-C₆-alkyl, C₁-C₆-alkoxy

b) methyl, methoxy

4. R⁴

a) hydrogen, C₁-C₆-alkyl, C₁-C₆-alkoxy, cyano

b) methyl, ethyl, isopropyl, methoxy, ethoxy, cyano,

5. R⁵

a) hydrogen, C₁-C₆-alkyl, heterocyclyl

b) hydrogen, methyl, isoxazolyl, which may be substituted by methyl,

6. R⁷

a) hydrogen, C₁-C₆-alkyl

b) hydrogen, methyl, ethyl

7. R⁸

a) C₁-C₆-alkyl

b) methyl, isopropyl

8. R⁹

a) C₁-C₆-alkyl

b) methyl, isopropyl

Preferred embodiments are those which display at least one or more ofthe abovementioned features (see items 1.-8.).

Particular preference is given to compounds of the formula I which havethe following combinations of the radicals R⁷, R⁸ and R⁹:

a) R⁷=hydrogen, R⁸=R⁹=C₁-C₆-alkyl

b) R⁷=R⁸=R⁹=C₁-C₆-alkyl

According to the invention, the herbicidal action of thebenzoylpyrazoles can be increased advantageously by substituting theN¹-position of the pyrazolyl ring by a branched C₁-C₆-alkyl group(α,α′-N-alkyl-substituted benzoylpyrazoles). In principle, this activityincrease occurs with all benzoylpyrazoles which have essential moietiesof the biophor shown in the Formula I which is responsible for theherbicidal action of this class of compounds. In this context, thebenzoylpyrazole group is an essential structural element. The othersubstituents present in this system can essentially be any radicals.However, preference is given to those benzoylpyrazoles which contain oneor more of the following biophoric structural elements: an alkenyl groupin the 3-position of the phenyl ring; a C₁-C₆-alkylsulfonyl group in the4-position of the phenyl ring; a halogen, C₁-C₆-alkyl- or C₁-C₆-alkoxygroup in the 2-position of the phenyl ring; a hydroxyl or alkoxy groupin the 5-position of the pyrazolyl ring.

In the context of the present invention, the following compounds of theformulae Ia1-Ia6 are preferred embodiments:

TABLE 1 No. R¹ R⁶ R⁷ R⁸ R⁹ Ia1.001 O—CH₃ H CH₃ CH₃ H Ia1.002 Cl H CH₃CH₃ H Ia1.003 CH₃ H CH₃ CH₃ H Ia1.004 O—CH₃ CH₃ CH₃ CH₃ H Ia1.005 Cl CH₃CH₃ CH₃ H Ia1.006 CH₃ CH₃ CH₃ CH₃ H Ia1.007 O—CH₃ CH₃ CH₃ CH₃ CH₃Ia1.008 Cl CH₃ CH₃ CH₃ CH₃ Ia1.009 CH₃ CH₃ CH₃ CH₃ CH₃ Ia1.010 O—CH₃ HCH₃ H i-C₃H₇ Ia1.011 Cl H CH₃ H i-C₃H₇ Ia1.012 CH₃ H CH₃ H i-C₃H₇Ia1.013 O—CH₃ H H i-C₃H₇ i-C₃H₇ Ia1.014 Cl H H i-C₃H₇ i-C₃H₇ Ia1.015 CH₃H H i-C₃H₇ i-C₃H₇ Ia1.016 O—CH₃ H C₂H₅ CH₃ CH₃ Ia1.017 Cl H C₂H₅ CH₃ CH₃Ia1.018 CH₃ H C₂H₅ CH₃ CH₃

Preference is furthermore given to compounds Ia2, in particular thecompounds Ia2.001-Ia2.018 which differ from the corresponding compoundsIa1.001-Ia1.018 in that R⁵ in the formula I is methoxy:

Preference is furthermore given to compounds Ia3, in particular thecompounds Ia3.001-Ia3.018 which differ from the corresponding compoundsIa1.001-Ia1.018 in that R⁵ in the formula I is methyl:

Preference is furthermore given to compounds Ia4, in particular thecompounds Ia4.001-Ia4.018 which differ from the corresponding compoundsIa1.001-Ia1.018 in that R⁵ in the formula I is ethyl:

Preference is furthermore given to compounds Ia5, in particular thecompounds Ia5.001-Ia5.018 which differ from the corresponding compoundsIa1.001-Ia1.018 in that R⁵ in the formula I is cyano:

Preference is furthermore given to compounds Ia6, in particular thecompounds Ia6.001-Ia6.018 which differ from the corresponding compoundsIa1.001-Ia1.018 in that R⁵ in the formula I is isopropyl:

The compounds of the formula I are essentially prepared by the processesdescribed in WO 98/50366.

Particularly suitable is a process which comprises acylating a pyrazoleof the formula II

with a carboxylic acid III or an activated derivative thereof

where the variables R¹ to R⁵ are as defined under claim 1 and L¹ ishydroxyl or a nucleophilically displaceable leaving group, andrearranging the acylation product in the presence or absence of acatalyst to the compounds I.

Compounds of the formula II are known from the literature orcommercially available. Alternatively, compounds of the formula II canbe prepared by the process described in DE 19910505.

Compounds of the formula III are disclosed, inter alia, in WO 98/50366and the literature references cited therein.

In the reaction scheme below, a possible synthesis route for preparingcompounds I starting from compounds A via the intermediates B, C and Dis described in an exemplary manner for R¹=methoxy, R²=methylsulfonyl,R³=R⁴=R⁵=R⁶=H, R⁷=R⁸CH₃, R⁹=H (compound Ia1.01):

The compounds I can be present in the form of their agriculturallyuseful salts, the type of salt generally not being important. Suitableare usually the salts of those bases which do not adversely affect theherbicidal action of I.

Suitable basic salts are, in particular, those of the alkali metals,preferably the lithium, sodium and potassium salts, those of thealkaline earth metals, preferably calcium, magnesium and barium salts,and those of the transition metals, preferably manganese, copper, zincand iron salts, ammonium salts, and ammonium salts which may carry oneto four C₁-C₄-alkyl, or hydroxy-C₁-C₄-alkyl substituents, one phenylor/benzyl substituent, preferably diethylammonium, diisopropylammonium,tetramethylammonium, tetrabutylammonium, trimelthylbenzylammonium, andtrimethyl-(2-hydroxyethyl)-ammonium salts, the phosphonium salts, thesulfonium salts, preferably tri-(C₁-C₄-)alkylsulfonium salts, and thesulfoxonium salts, preferably tri-(C₁-C₄-)alkylsulfoxonium salts.

The compounds I and their agriculturally useful salts are suitable, bothin the form of isomer mixtures and in the form of the pure isomers, asherbicides. The herbicidal compositions comprising compounds I controlvegetation on non-crop areas very efficiently, especially at high ratesof application. They act against broad-leaved weeds and harmful grassesin crops such as wheat, rice, maize, soya and cotton without causing anysignificant damage to the crop plants. This effect is mainly observed atlow rates of application.

Depending on the application method used, the compounds I, or thecompositions comprising them, can additionally be/employed in a furthernumber of crop plants for eliminating undesirable plants. Examples ofsuitable crops are the following:

Allium cepa, Ananas comosus, Arachis hypogaea, Asparagus officinalis,Beta vulgaris spec. altissima, Beta vulgaris spec. rapa, Brassica napusvar. napus, Brassica napus var. napobrassica, Brassica rapa var.silvestris, Camellia sinensis, Carthamus tinctorius, Caryaillinoinensis, Citrus limon, Citrus sinensis, Coffea arabica (Coffeacanephora, Coffea liberica), Cucumis sativus, Cynodon dactylon, Daucuscarota, Elaeis guineensis, Fragaria vesca, Glycine max, Gossypiumhirsutum, (Gossypium arboreum, Gossypium herbaceum, Gossypiumvitifolium), Helianthus annuus, Hevea brasiliensis, Hordeum vulgare,Humulus lupulus, Ipomoea batatas, Juglans regia, Lens culinaris, Linumusitatissimum, Lycopersicon lycopersicum, Malus spec., Manihotesculenta, Medicago sativa, Musa spec., Nicotiana tabacum (N.rustica),Olea europaea, Oryza sativa, Phaseolus lunatus, Phaseolus vulgaris,Picea abies, Pinus spec., Pisum sativum, Prunus avium, Prunus persica,Pyrus communis, Ribes sylvestre, Ricinus communis, Saccharumofficinarum, Secale cereale, Solanum tuberosum, Sorghum bicolor (s.vulgare), Theobroma cacao, Trifolium pratense, Triticum aestivum,Triticum durum, Vicia faba, Vitis vinifera and Zea mays.

In addition, the compounds I may also be used in crops which toleratethe action of herbicides owing to breeding, including geneticengineering methods.

The herbicidal compositions or the active compounds can be applied pre-or post-emergence. If the active compounds are less well tolerated bycertain crop plants, application techniques may be used in which theherbicidal compositions are sprayed, with the aid of the sprayingequipment, in such a way that they come into contact as little aspossible, if at all, with the leaves of the sensitive crop plants, whilethe active compounds reach the leaves of undesirable plants growingunderneath, or the bare soil surface (post-directed, lay-by).

The compounds I, or the herbicidal compositions comprising them, can beused for example in the form of ready-to-spray aqueous solutions,powders, suspensions, also highly-concentrated aqueous, oily or othersuspensions or dispersions, emulsions, oil dispersions, pastes, dusts,materials for broadcasting or granules, by means of spraying, atomizing,dusting, broadcasting or watering. The use forms depend on the intendedaims; in any case, they should ensure a very fine distribution of theactive compounds according to the invention.

Essentially, suitable inert auxiliaries include: mineral oil fractionsof medium to high boiling point, such as kerosene and diesel oil,furthermore coal tar oils and oils of vegetable or animal origin,aliphatic, cyclic and aromatic hydrocarbons, e.g. paraffin,tetrahydronaphthalene, alkylated naphthalenes and their derivatives,alkylated benzenes and their derivatives, alcohols such as methanol,ethanol, propanol, butanol and cyclohexanol, ketones such ascyclohexanone, or strongly polar solvents, e.g. amines such asN-methylpyrrolidone, and water.

Aqueous use forms can be prepared from emulsion concentrates,suspensions, pastes, wettable powders or water-dispersible granules byadding water. To prepare emulsions, pastes or oil dispersions, thecompounds I, either as such or dissolved in an oil or solvent, can behomogenized in water by means of a wetting agent, tackifier, dispersantor emulsifier. Alternatively, it is possible to prepare concentratescomprising active substance, wetting agent, tackifier, dispersant oremulsifier and, if desired, solvent or oil, which are suitable fordilution with water.

Suitable surfactants are the alkali metal salts, alkaline earth metalsalts and ammonium salts of aromatic sulfonic acids, e.g. ligno-,phenol-, naphthalene- and dibutylnaphthalenesulfonic acid, and of fattyacids, alkyl- and alkylarylsulfonates, alkyl sulfates, lauryl ethersulfates and fatty alcohol sulfates, and salts of sulfated hexa-, hepta-and octadecanols, and also of fatty alcohol glycol ethers, condensatesof sulfonated naphthalene and its derivatives with formaldehyde,condensates of naphthalene, or of the naphthalenesulfonic acids withphenol and formaldehyde, polyoxyethylene octylphenol ether, ethoxylatedisooctyl-, octyl- or nonylphenol, alkylphenyl or tributylphenylpolyglycol ether, alkylaryl polyether alcohols, isotridecyl alcohol,fatty alcohol/ethylene oxide condensates, ethoxylated castor oil,polyoxyethylene alkyl ethers or polyoxypropylene alkyl ethers, laurylalcohol polyglycol ether acetate, sorbitol esters, lignin-sulfite wasteliquors or methylcellulose.

Powders, materials for broadcasting and dusts can be prepared by mixingor grinding the active substances together with a solid carrier.

Granules, e.g. coated granules, impregnated granules and homogeneousgranules, can be prepared by binding the active compounds to solidcarriers. Solid carriers are mineral earths, such as silicas, silicagels, silicates, talc, kaolin, limestone, lime, chalk, bole, loess,clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate,magnesium oxide, ground synthetic materials, fertilizers such asammonium sulfate, ammonium phosphate and ammonium nitrate, ureas, andproducts of vegetable origin, such as cereal meal, tree bark meal, woodmeal and nutshell meal, cellulose powders, or other solid carriers.

The concentrations of the active compounds I in the ready-to-usepreparations can be varied within wide ranges. In general, theformulations comprise from about 0.001 to 98% by weight, preferably 0.01to 95% by weight, of at least one active compound. The active compoundsare employed in a purity of from 90% to 100%, preferably 95% to 100%(according to the NMR spectrum).

The compounds I according to the invention can be formulated, forexample, as follows:

I. 20 parts by weight of a compound I are dissolved in a mixturecomposed of 80 parts by weight of alkylated benzene, 10 parts by weightof the adduct of 8 to 10 mol of ethylene oxide to 1 mol of oleic acidN-monoethanolamide, 5 parts by weight of calcium dodecylbenzenesulfonateand 5 parts by weight of the adduct of 40 mol of ethylene oxide to 1 molof castor oil. Pouring the solution into 100,000 parts by weight ofwater and finely distributing it therein gives an aqueous dispersionwhich comprises 0.02% by weight of the active compound.

II. 20 parts by weight of a compound I are dissolved in a mixturecomposed of 40 parts by weight of cyclohexanone, 30 parts by weight ofisobutanol, 20 parts by weight of the adduct of 7 mol of ethylene oxideto 1 mol of isooctylphenol and 10 parts by weight of the adduct of 40mol of ethylene oxide to 1 mol of castor oil. Pouring the solution into100,000 parts by weight of water and finely distributing it thereingives an aqueous dispersion which comprises 0.02% by weight of theactive compound.

III. 20 parts by weight of a compound I are dissolved in a mixturecomposed of 25 parts by weight of cyclohexanone, 65 parts by weight of amineral oil fraction of boiling point 210 to 280° C. and 10 parts byweight of the adduct of 40 mol of ethylene oxide to 1 mol of castor oil.Pouring the solution into 100,000 parts by weight of water and finelydistributing it therein gives an aqueous dispersion which comprises0.02% by weight of the active compound.

IV. 20 parts by weight of a compound I are mixed thoroughly with 3 partsby weight of sodium diisobutylnaphthalene-sulfonate, 17 parts by weightof the sodium salt of a lignosulfonic acid from a sulfite waste liquorand 60 parts by weight of pulverulent silica gel, and the mixture isground in a hammer mill. Finely distributing the mixture in 20,000 partsby weight of water gives a spray mixture which comprises 0.1% by weightof the active compound.

V. 3 parts by weight of a compound I are mixed with 97 parts by weightof finely divided kaolin. This gives a dust which comprises 3% by weightof the active compound.

VI. 20 parts by weight of a compound I are mixed intimately with 2 partsby weight of calcium dodecylbenzenesulfonate, 8 parts by weight of fattyalcohol polyglycol ether, 2 parts by weight of the sodium salt of aphenol/urea/formaldehyde condensate and 68 parts by weight of aparaffinic mineral oil. This gives a stable oily dispersion.

VII. 1 part by weight of a compound I is dissolved in a mixture composedof 70 parts by weight of cyclohexanone, 20 parts by weight ofethoxylated isooctylphenol and 10 parts by weight of ethoxylated castoroil. This gives a stable emulsion concentrate.

VIII. 1 part by weight of a compound I is dissolved in a mixturecomposed of 80 parts by weight of cyclohexanone and 20 parts by weightof Wettol® EM 31 (nonionic emulsifier based on ethoxylated castor oil).This gives a stable emulsion concentrate.

To widen the activity spectrum and to achieve synergistic effects, thecompounds I may be mixed with a large number of representatives of otherherbicidal or growth-regulating active compound groups and then appliedconcomitantly. Suitable components for mixtures are, for example,1,2,4-thiadiazoles, 1,3,4-thiadiazoles, amides, aminophosphoric acid andits derivatives, aminotriazoles, anilides, (het)aryloxyalkanoic acidsand their derivatives, benzoic acid and its derivatives,benzothiadiazinones, 2-aroyl-1,3-cyclohexanediones, hetaryl arylketones, benzylisoxazolidinones, meta-CF₃-phenyl derivatives,carbamates, quinolinecarboxylic acid and its derivatives,chloroacetanilides, cyclohexane-1,3-dione derivatives, diazines,dichloropropionic acid and its derivatives, dihydrobenzofurans,dihydrofuran-3-ones, dinitroanilines, dinitrophenols, diphenyl ethers,dipyridyls, halocarboxylic acids and their derivatives, ureas,3-phenyluracils, imidazoles, imidazolinones,N-phenyl-3,4,5,6-tetrahydrophthalimides, oxadiazoles, oxiranes, phenols,aryloxy- and hetaryloxyphenoxypropionic esters, phenylacetic acid andits derivatives, phenylpropionic acid and its derivatives, pyrazoles,phenylpyrazoles, pyridazines, pyridinecarboxylic acid and itsderivatives, pyrimidyl ethers, sulfonamides, sulfonylureas, triazines,triazinones, triazolinones, triazolecarboxamides and uracils.

It may furthermore be advantageous to apply the compounds I, alone orelse concomitantly in combination with other herbicides, in the form ofa mixture with other crop protection agents, for example together withagents for controlling pests or phytopathogenic fungi or bacteria. Alsoof interest is the miscibility with mineral salt solutions, which areemployed for treating nutritional and trace element deficiencies.Non-phytotoxic oils and oil concentrates may also be added.

The application rates of the active compound are from 0.001 to 3.0,preferably 0.01 to 1.0 kg/ha of active substance (a.s.), depending onthe control target, the season, the target plants and the growth stage.

EXAMPLE 1(5-Methoxy-1-cyclopropyl-1H-pyrazol-4-yl)(4-methylsulfonyl-2-methoxy-3-vinylphenyl)methanonea) 2-Methoxy-6-methylsulfanylbenzaldehyde

At 0° C. NaSMe (12.2 g, 0.18 mol) was added a little at a time to asolution of 2-chloro-6-methoxybenzaldehyde (20 g, 0.12 mol) in NMP (12.2g, 0.18 mol). The solution was stirred at 0° C. for 3 h, and its colorchanged to black. The solution was subsequently stirred intoapproximately 2 l of ice-water and acidified to pH=3 using 10% strengthHCl, and the precipitate was filtered off with suction.

Yield: 13.6 g (65%). ¹H-NMR(270 MHz, CDCl₃): 2.4 (s, 3H); 3.9 (s, 3H);6.8 (d, 1H); 6.95 (d, 1H); 7.42 (d, 1H); 10.6 (s, 1H).

b) 3-Bromo-2-methoxy-6-methylsulfanylbenzaldehyde

Bromine (28.8 g, 0.18 mol) (dissolved in dioxane (500 ml)) was addeddropwise to a solution of 2-methoxy-6-methylsulfanylbenzaldehyde (22 g,0.12 mol) in dioxane (500 ml), and the mixture was stirred at 50° C. for6 h. The mixture was then concentrated, the residue was taken up inCH₂Cl₂ and the mixture was washed with water, dried over MgSO₄ andconcentrated. The solid was recrystallized from diisopropyl ether.

Yield: 17.5 g (56%). ¹H-NMR(270 MHz, CDCl₃): 2.40 (s, 3H); 3.90 (s, 3H);6.72 (d, 1H); 6.85 (d, 1H); 7.42 (m, 1H); 10.6 (s, 1H).

c) 1-Bromo-2-methoxy-4-methylsulfanyl-3-vinylbenzene

At 0° C., potassium tert-butoxide (6.2 g, 55.4 mmol) was added to asolution of methyltriphenylphosphoniumbromide (19.7 g, 55.4 mmol) in THF(180 ml). At from −10 to −5° C.,3-bromo-2-methoxy-6-methylsulfanylbenzaldehyde (12 g, 46 mmol) dissolvedin THF (180 ml) was then added, and the mixture was stirred overnight atRT for 7 h. The mixture was filtered, and the solution was admixed withH₂O (200 ml) and MTBE (200 ml) and then extracted with MTBE (200 ml).The combined organic phases were dried over MgSO₄ and concentrated.Chromatography (cyclohexane→cyclohexane/EtOAc 9:1) gave1-bromo-2-methoxy-4-methylsulfanyl-3-vinylbenzene.

Yield: 4.67 g (39%). ¹H-NMR(270 MHz, CDCl₃): 2.40 (s, 3H); 3.70 (s, 3H);5.62 (dd, 1H); 5.90 (dd, 1H); 6.70-6.90 (m, 2H); 7.40 (s, 1H).

d) 2-Methoxy-4-methylsulfanyl-3-vinylbenzoic acid

At −100° C., n-BuLi (25 ml, 15% in n-hexane, 4.1 mmol) was added to asolution of 1-bromo-2-methoxy-4-methylsulfanyl-3-vinylbenzene (7 g, 31.3mmol) in THF (300 ml), and the mixture was stirred at −100° C. for 20min. At −100° C., CO₂ was then introduced (exothermic reaction up to−60° C.). At −80 to −90° C., the mixture was then stirred for another 1h, and NaOH (100 ml) was added dropwise at −40° C. The solution wasstirred into EtOAc (400 ml), and the mixture was extracted 3× with 5%strength NaOH and acidified to pH=1 using 10% strength HCl. The H₂Ophase was extracted with EtOAc (300 ml), and the combined organic phaseswere dried over MgSO₄ and concentrated.

Yield: 6.8 g (98%). ¹H-NMR(270 MHz, CDCl₃): 1.90 (s, 3H); 2.42 (s, 3H);3.62 (s, 3H); 5.50-5.80 (m, 2H); 6.58-6.65 (m, 1H); 7.1 (d, 1H); 7.6 (d,1H).

e) 4-Methylsulfonyl-2-methoxy-3-vinylbenzoic acid

NaWO₄ (cat.) was added to a solution of2-methoxy-4-methylsulfanyl-3-vinylbenzoic acid, (6.8 g, 30 mmol) in AcOH(130 ml), H₂O₂ (8.6 ml, 76 mmol) was added dropwise and the mixture wasstirred at room temperature for 5 h. The solution was concentrated, theresidue was taken up in methylene chloride and the mixture was driedover magnesium sulfate and concentrated.

Yield: 4.8 g (61%). ¹H-NMR(270 MHz, CDCl₃): 3.20 (s, 3H); 3.70 (s, 3H);5.65-5.90 (m, 2H); 7.0-7.20 (m, 1H); 7.65-7.95 (m, 2H).

f)5-Hydroxy-1-isopropyl-1H-pyrazol-4-yl)-(4-methylsulfonyl-2-methoxy-3-vinylphenyl)methanone

SOCl₂ (1.2 g, 10 mmol) was added to a solution of4-methylsulfonyl-2-methoxy-3-vinylbenzoic acid (1.6 g, 6 mmol) intoluene (60 ml) and the mixture was heated at reflux for 2 h. Themixture was then concentrated and the product was added to a solution ofN-isopropylpyrazolone (6 mmol), K₂CO₃ (1.6 g, 11.6 mmol) in DME (30 ml)and the mixture was stirred at RT overnight. The mixture wassubsequently heated at reflux for 2 h and concentrated and the residuewas dissolved in H₂O. The H₂O phase was extracted 3× with CH₂Cl₂, andthe combined organic phases were dried over MgSO₄ and concentrated.

EXAMPLE 2

In the manner as described in Example 1, it is possible to obtain thefollowing compounds:

Ia1

Ex. No. R¹ R⁶ R⁷ R⁸ R⁹ Mp. 2.01 O—CH₃ H CH₃ CH₃ H 57-60° C. 2.02 Cl HCH₃ CH₃ H 2.03 CH₃ H CH₃ CH₃ H 134-135° C. 2.04 O—CH₃ CH₃ CH₃ CH₃ H 2.05Cl CH₃ CH₃ CH₃ H 2.06 CH₃ CH₃ CH₃ CH₃ H 2.07 O—CH₃ CH₃ CH₃ CH₃ CH₃ 2.08Cl CH₃ CH₃ CH₃ CH₃ 2.09 CH₃ CH₃ CH₃ CH₃ CH₃ 2.10 O—CH₃ H CH₃ H i-C₃H₇2.11 Cl H CH₃ H i-C₃H₇ 2.12 CH₃ H CH₃ H i-C₃H₇ 2.13 O—CH₃ H H i-C₃H₇i-C₃H₇ 2.14 Cl H H i-C₃H₇ i-C₃H₇ 2.15 CH₃ H H i-C₃H₇ i-C₃H₇ 2.16 O—CH₃ HC₂H₅ CH₃ CH₃ 2.17 Cl H C₂H₅ CH₃ CH₃ 2.18 CH₃ H C₂H₅ CH₃ CH₃ 2.19 OCH₃ HCH₃ CH₃ CH₃ 57-60° C. 2.20 CH₃ H CH₃ CH₃ CH₃ 122-124° C. 2.21 OC₂H₅ HCH₃ CH₃ H 123-124° C. 2.22 OC₂H₅ H CH₃ CH₃ CH₃ 106-108° C. 2.23 Cl H CH₃CH₃ CH₃ 117-125° C.

EXAMPLE 3

In the same manner as described in Example 1, it is possible to obtainthe following compounds:

Ia3

Ex. No. R¹ R⁶ R⁷ R⁸ R⁹ m.p. 3.1¹⁾ Cl H H CH₃ CH₃ 44-54° C. 3.2¹⁾ CH₃ H HCH₃ CH₃ 58-68° C. 3.3¹⁾ CH₃ H CH₃ CH₃ CH₃ 63-74° C. 3.4²⁾ Cl H CH₃ CH₃CH₃ 172-174° C. ¹⁾R⁵ = CH₃ ²⁾R⁵ = 5-methylisoxazol-3-yl

EXAMPLE 4

The herbicidal activity of the compounds of the formula I was shown bygreenhouse experiments:

The culture containers used are plastic pots containing loamy sand withapproximately 3.0% of humus as the substrate. The seeds of the testplants are sown separately for each species.

For the pre-emergence treatment, the active compounds, which have beensuspended or emulsified in water, were applied directly after sowing bymeans of finely distributing nozzles. The containers were irrigatedgently to promote germination and growth and subsequently covered withtransparent plastic hoods until the plants have rooted. This covercauses uniform germination of the test plants, unless this was adverselyaffected by the active compounds.

For the post-emergence treatment, the test plants were first grown to aheight of 3 to 15 cm, depending on the plant form, and only then treatedwith the active compounds which have been suspended or emulsified inwater. The test plants were for this purpose either sown directly andgrown in the same containers, or they were first grown separately asseedlings and transplanted into the test containers a few days prior totreatment. The application rate for the post-emergence treatment was0.25, 0.125 or 0.0625 kg of active substance (a.s.)/ha.

Depending on the species, the plants were kept at 10-25° C. or 20-35° C.The test period extended over 2 to 4 weeks. During this time, the plantsare tended, and their response to the individual treatments wasevaluated.

The evaluation was carried out using a scale from 0 to 100. 100 means noemergence of the plants, or complete destruction of at least the aerialparts and 0 means no damage, or normal course of growth.

The plants used in the greenhouse experiments were composed of thefollowing species:

Code Common name AMARE pigweed CHEAL lambsquarter ECHCG barnyardgrassPOLPE ladysthumb SETVI green foxtail SINAL white mustard SOLNI blacknightshade

TABLE 1 Herbicidal activity when used by the post-emergence method in agreenhouse

Application rate (kg of a.s./ha) Test plants 0.125 0.0625 ECHCG 95 95SETVI 95 95 CHEAL 100 100 POLPE 100 100 SINAL 98 98

We claim:
 1. A pyrazole of the formula I

where: R¹ is hydrogen, nitro, halogen, cyano, thiocyanato, C₁-C₆-alkyl,C₁-C₆-alkoxy, C₁-C₆-haloalkyl, C₁-C₆-alkylthio, C₂-C₆-alkenyl,C₂-C₆-alkynyl; R² is —S(O)_(n)R¹⁰, —SO₂OR¹¹, —SO₂NR¹¹R¹², —NR¹²SO₂R¹³,—NR¹²COR¹³, —PO(OR¹⁴)(OR¹⁵); R³ is hydrogen, halogen, C₁-C₆-alkyl,C₁-C₆-haloalkyl, C₁-C₆-alkoxy, C₂-C₆-alkenyl or C₂-C₆-alkynyl; R⁴, R⁵are hydrogen, nitro, halogen, cyano, thiocyanato, C₁-C₆-alkyl,C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, C₂-C₆-alkenyl, C₄-C₆-cycloalkenyl,C₂-C₆-alkynyl, C₁-C₆-alkylthio, C₁-C₆-haloalkoxyl, —COR¹⁴, —CO₂R¹⁴,—COSR¹⁴, —CONR¹⁴R¹⁵, —C(R¹⁶)═NR¹⁷, —PO(OR¹⁴)(OR¹⁵), C₁-C₄-alkyl, whichcarries a radical from the following group: —COR¹⁴, —CO₂R¹⁴, —COSR¹⁴,—CONR¹⁴R¹⁵ or —C(R¹⁶)═NR¹⁷; heterocyclyl, heterocyclyl-C₁-C₄-alkyl,phenyl, phenyl-C₁-C₄-alkyl, hetaryl or hetaryl-C₁-C₄-alkyl, where thesix last-mentioned radicals may be substituted; or R⁴ and R⁵ togetherform a C₂-C₆-alkanediyl chain which may be mono- to tetrasubstituted byC₁-C₄-alkyl and/or may be interrupted by oxygen or sulfur or anunsubstituted or C₁-C₄-alkyl-substituted nitrogen; R⁶ is hydrogen,halogen, C₁-C₆-alkyl, C₁-C₆-alkoxy, C₃-C₈-cycloalkyl; R⁷, R₈, R⁹ arehydrogen, C₁-C₆-alkyl, where the alkyl group may be unsubstituted ormono- or polysubstituted by halogen or cyano and the radicals R⁷, R⁸ andR⁹ are in each case identical or different, but at most one of theradicals of the group R⁷, R⁸ and R⁹ is hydrogen; n is 0, 1 or 2; R¹⁰ isC₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy-C₂-C₆-alkyl, C₃-C₆-alkenyl orC₃-C₆-alkynyl; R¹¹ is hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl,C₁-C₆-alkoxy-C₂-C₆-alkyl, C₃-C₆-alkenyl or C₃-C₆-alkynyl; R¹² ishydrogen or C₁-C₆-alkyl; R¹³ is C₁-C₆-alkyl or C₁-C₆-haloalkyl; R¹⁴ ishydrogen, C₁-C₆-alkyl, C₃-C₆-cycloalkyl, C₁-C₆-haloalkyl, C₃-C₆-alkenyl,C₃-C₆-alkynyl, phenyl or benzyl, where the two last-mentioned radicalsmay be partially or fully halogenated and/or may carry one to threeradicals from the following group: nitro, cyano, C₁-C₄-alkyl,C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy, C₁-C₄-alkylcarbonyl orC₁-C₄-alkoxycarbonyl; R¹⁵ is hydrogen, C₁-C₆-alkyl, C₃-C₆-alkenyl orC₃-C₆-alkynyl; or R¹⁴ and R¹⁵ together form a C₂-C₆-alkanediyl chainwhich may be mono- to tetrasubstituted by C₁-C₄-alkyl and/or may beinterrupted by oxygen or sulfur or an unsubstituted orC₁-C₄-alkyl-substituted nitrogen; R¹⁶ is hydrogen, C₁-C₆-alkyl,C₁-C₆-haloalkyl, C₁-C₆-alkoxy, C₁-C₆-alkoxycarbonyl, C₃-C₆-cycloalkyl,C₂-C₆-alkenyl, C₂-C₆-alkynyl, phenyl or benzyl, where the twolast-mentioned radicals may be partially or fully halogenated and/or maycarry one to three radicals from the following group: nitro, cyano,C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy,C₁-C₄-alkylcarbonyl or C₁-C₄-alkoxycarbonyl; R¹⁷ is C₁-C₆-alkyl,C₁-C₆-haloalkyl, C₃-C₆-cycloalkyl, C₃-C₆-alkenyl, C₃-C₆-alkynyl,C₁-C₆-alkoxy, C₁-C₆-haloalkoxy, C₃-C₆-cycloalkoxy, C₃-C₆-alkenyloxy,C₃-C₆-alkynyloxy, phenyl, benzyl or benzyloxy, where the threelast-mentioned radicals may be partially or fully halogenated and/or maycarry one to three radicals from the following group: nitro, cyano,C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy,C₁-C₄-alkylcarbonyl or C₁-C₄-alkoxycarbonyl; and its tautomers andagriculturally useful salts.
 2. A pyrazole as claimed in claim 1 whereR⁷ is hydrogen or C₁-C₆-alkyl.
 3. A pyrazole as claimed in claim 1 whereR⁸ is C₁-C₆-alkyl.
 4. A pyrazole as claimed in claim 1 where R⁹ isC₁-C₆-alkyl.
 5. A pyrazole as claimed in claim 1 where R⁷ is hydrogenand R⁸ and R⁹ are C₁-C₆-alkyl.
 6. A pyrazole as claimed in claim 1 whereR¹ is hydrogen, C₁-C₆-alkoxy, C₁-C₆-alkyl or halogen.
 7. A pyrazole asclaimed in claim 1 where R² is in the para position to thepyrazolylcarbonyl group and has the following meaning: —SO₂R¹⁰, —SO₂OR¹¹and R¹⁰ and R¹¹ are each C₁-C₆-alkyl.
 8. A pyrazole as claimed in claim1 where R³ is hydrogen or C₁-C₆-alkyl.
 9. A pyrazole as claimed in claim1 where R⁴ is hydrogen or C₁-C₆-alkyl.
 10. A pyrazole as claimed inclaim 1 where R⁵ is hydrogen or C₁-C₆-alkyl.
 11. A pyrazole as claimedin claim 1 where R³, R⁴ and R⁵ are each identical and are hydrogen. 12.A pyrazole as claimed in claim 1 where R¹ is halogen, C₁-C₆-alkyl orC₁-C₆-alkoxy.
 13. A process for preparing a pyrazole as claimed in claim1 which comprises acylating a pyrazole of the formula II

with a carboxylic acid III or an activated derivative thereof

where the variables R¹ to R⁵ are as defined under claim 1 and L¹ ishydroxyl or a nucleophilically displaceable leaving group, andrearranging the acylation product in the presence or absence of acatalyst to the compounds I.
 14. A composition comprising a herbicidallyeffective amount of at least one pyrazole of the formula I or anagriculturally useful salt of I as claimed in claim 1 and auxiliarieswhich are customary for formulating crop protection agents.
 15. Aprocess for preparing a herbicidally active composition as claimed inclaim 14 which comprises mixing a herbicidally effective amount of atleast one pyrazole of the formula I or an agriculturally useful salt ofI and auxiliaries which are customary for formulating crop protectionagents.
 16. A method for controlling undesirable vegetation whichcomprises allowing a herbicidally effective amount of at least onepyrazole of the formula I or an agriculturally useful salt of I asclaimed in claim 1 to act on plants, their habitat